How reliable is new wrist based power on Garmin Fenix 7

It seems consistent in that it registers similar power for similar runs but as far as accuracy, who knows. Running power is like the wild west. No standard of measurement and everyone is out there doing their own thing. A 200w effort on my stryd will say 300 on Garmin. Who's right? Probably both. They just measure very differently so making cross platform comparisons is impossible.

So if stryd is what you have, use that, it's accurate. If Garmin is what you have, use that, it's accurate too. So is apple if that's your thing. Just don't ever switch platforms and try to compare the data as it won't work

Agree with Skyewalkr, the information is consistent but i certainly wouldn't consider it accurate or precise in any way. Just looking at the data available to the watch in order to estimate this tells you all you need to know. A change in atmospheric pressure is indistinguishable to the watch from a change in elevation so it has to guess whether you're going up or downhill. We all know how accurate wrist based elevation is. Your watch knows nothing about gait, style or efficiency of your running so again has to effectively guess whether you're doing a canter or a gallop (in horse terms, obvs). Next we can look at speed/pace, which is an often discussed topic where accuracy is called into question. Mangle all of these together and I'd say they're lucky to get the consistency they are getting, let alone accuracy.

The data will tell you how comparatively hard you're working compared to last week. That's nice, but for run training it's not relevant in the same way it is for cycling. On a bike raw power is one of two ways to attain and maintain speed, alongside aerodynamics. Not so for running where form plays a much more important role, and reducing raw power input often leads to faster times. It's also very much harder to train to power when running, you can run up a hill to increase power, or you can run faster. Neither of these help with training for a flat marathon though, because one trains you for hills and the other for running at a faster pace.

The absolute value of power from Garmin is very different from Stryd, but both are very responsive to changes in pace and form for horizontal power.

Both will have the same limitations when adjusting for slope, wind and unequal terrain (trail-running).

I keep using Stryd:

- to upload its power to the Stryd PowerCenter. I like how Stryd PowerCenter helps you manage your power-duration curve and your critical power.

- to provide real-time pace information. I find that Stryd is easier to calibrate precisely (even for track running)

At the same time, I am using Garmin's native power because:

- I like how Garmin's power can be used to create native structured workouts and native power zones. I let Garmin send its power to Garmin Connect and TrainingPeaks, Strava, etc.That doesn't bother me it has replaced Stryd's power there.

- I keep using Stryd as a pace sensor because it is a pain to calibrate the HRMPro manually, and I have not been able to get consistent results.

- When using an accurate pace information, I didn't find differences between the wrist-based and the HRMPro-based power calculation.

forums.garmin.com/.../a-quick-test-of-wrist-power-vs-hrm-pro-power-for-running

Running up hill develops strength and proper form for running up hill. Specificity is important in training, and running uphill and on the flat are very different activities, using different muscles. Runnning a marathon and sprinting 100m also use different muscles and form, otherwise Kipchoge would be racing Bolt. Running isn't just one thing, so power numbers are much less relevant than in cycling. Relative power for a given form and setting is kind of helpful, but it's not the game changer power was in cycling, or the game changer some sports companies are trying to suggest it is. At least Garmin down played this one, probably after getting burned with running dynamics which are also pretty much useless.

TLDR: there are a lot of runners using way too many watts to go nowhere fast

lustyd said:

Relative power for a given form and setting is kind of helpful, but it's not the game changer power was in cycling

I am not arguing in comparison to biking. Running power is still the best proxy for "running work" even given the challenges of modeling and measuring it. Other measures work too for any good training plan: HR was OK until GPS-capable wearables made pace-based models work just fine on flat terrain. Now we have wearable power sensors...

lustyd said:

Runnning a marathon and sprinting 100m also use different muscles and form, otherwise Kipchoge would be racing Bolt

Sure. This is what I disagree with.

lustyd said:

you can run up a hill to increase power, or you can run faster. Neither of these help with training for a flat marathon though

But don't take my word for it. According to Joe Friel :

"* Hilly run. Besides the long run, this is the most valuable workout you can do early in the season. These will give you not only strength for hills on the marathon course, but also a more powerful stride."

https://joefrieltraining.com/the-triathlete-as-fast-marathoner/

Jeff Galloway also incorporates hill runs in his marathon plan training.

Finally, Kipchoge was running tempo hill drills, and other tempo on cross-country tracks for his training for the Berlin Marathon.

https://runningscience.co.za/elite-athletes-training-log/eliud-kipchoge/

So, if you find some coach recommending to avoid hill workouts during a marathon plan, please share.

Yeah, I’ve heard that “hills are speedwork in disguise”. And marathon training has plenty of speedwork (not the same kind as plans for shorter distances, though.)

Sadly I think you're completely missing my point. You should try to understand the mechanics of running more if you want to improve running. Numbers will not help you.

you see? like i said, running power is the wild west. nobody agrees on anything. i like stryd and use stryd, but if they go away or expand the paid subscription model, i'll happily use garmin wrist running power and not think twice about it. 

I've been comparing Garmin Power to Stryd for the past month or so.  From my experience, when my pace is 9:00 min/mile or slower, the shape of the Stryd and Garmin power curves are very similar, though on different scales.  Garmin power is approximately 50-70 watts more than what Stryd reports, but of course these are made up numbers anyways.  When I do tempo runs or intervals, these two power curves diverge more with Garmin power about 100-140 watts more than Stryd.  I think eventually I will switch to Garmin power especially now that I also have the HRM Pro so I can get running dynamics metrics.